Manufacture of artificial filaments or threads



April 16, 1935. H. DREYFUS m9979633 MANUFACTURE OF ARTIFICIAL FILAMENTS OR THREADS Filed April 4, 1929 F162, Flaio O o o /G *O Ag@ 4Q@ D n o v o O O 0 O o 0 l.

' HENRY DREYFUS AHM-MCL; S

Patented Apr. 16, 1935 v Y UNIT-i511) STATES PATENT orti-ce MAN UFACTURE `OF ARTIFICIAL FILAMENTS .OR THREADS Henry Dreyfus, London, England Application April 4, 1929, Serial No. `352,441

In Great Britain April 10, 192,8

sola-ima (c1. 11acy rllhis.invention relates to the manufacture of or :threads .tofollowa path of.3.to.6 yards ormore articial silk and other .filaments or `threads from in length .through vthe .evaporative medium .in the solutions ofcellulose derivatives, for example, chamber, and winding the solidified iilaments or cellulose acetate or other cellulose esters o-r threads mechanically .outside the chamber.

cellulose .eti-1ers, phy dry-spinning .or .evaporative Itis found that,.under.any givenset of spinning 5 methods. Y conditions, .which will, of course, vary with the .In .accordance -with the invention described ,in denier spun and the spinning solutions employed, U. S. patent-speciiication No. 1,602,125, artificial the laments .obtained .in .accordance with the lamentsforxthreads lare produced by extruding a present invention .display a remarkable regularity .1.0 solution containing cellulose. 4acetate .or'other as regards their physical characteristics. 10 cellulose derivative dissolved in a volatile ,solvent It is .also .of interest to note that owing Lto the liguidthrough one ormone jets or nozzleslocated length of the path .traversed by .the laments in the -upm-ir l:pa-rt oaspinning chamber, leading Within the spinning Chamber, it iS Possible t0 the filaments or threads downwards vthrough an secure complete 01 Substantially Complete 19- 1'5 atmosphere -of Warm or hot 4air `or other -gaseous moval .of the volatile .solventibefore the laments 15 evaporative :medium within the spinning .chamissue ,from .the .spinning chamber. In this Way, ber, Vand winding the solidified laments yesultloss of volatile .solvent '.by ,evaporation outside ing from .the.evaporation .of the volatile ,solvent the chamber can be prevented. This result is liquid mechanically on vapparatus ,located 1outside ,achieved without decreasing ,the .concentration .the chamber. The air .or other Agaseous evaporaof the solvent .vapours 5in the Aair or .other .evapo- 20 tive medium .is heated.bysuitableheatingdevices, rative medium which .is led from the spinning and is ,preferably `caused Ato lovvLinlcounter-curchamber .to the recoveryplalt, .WhCll iS thus .rent to. thepassage of the filaments. The laenabled 110 Work linder the Optimum COIldtOnS' ments are associated into ,threads on .their Way to 0f eCeHCyf.

the winding device, and .may .be wound .thereon .In one form of apparatus constructed in ac- 25 either with or without twisting. cordance with this invention, the laments are .As explained in the Vabove specification, .the led from spinning jets .or nozzles in the upper time during-which the filaments are .exposed kto .part of .the chamber to a point 'below vthe .point .the .evaporative influence of .the heated air .or at which the'laments emerge from the chamother .gasbefore issuing from the ychamber must ber, andV are led back'V in an upward .direction .to 3@ be such as -to .ensure .that the .volatilesolvents are the .point of exit, the filaments thus following .sufficiently .evaporated .and .the lilaments ,sufa. more -or less .tortuous path in the chamber. '.ciently solidified in .their travel through the In this .case, the lower part .of the spinning chamber. The necessary .time of .such exposure chamber is tted Witha ,guide or roller or simivaries with .the boiling .points .andquantity .of the lar device, .around which `the filaments are 35 volatile liquids .used in the .spinning solutions, caused .to .pass on their way to the point at .the .denier .of .the filaments, and the temperature which they leave the chamber. The distance .and speed of .thecurrent of .air A,orother .evaporabetween the jets or nozzles .and .the guide, roller tive medium passing through thev chamber. or ,similar .device `around which the iilaments 40 Usually .the period .taken by .the .laments in pass, may be shorter than the path of the iila- 40 ,passing from the jets .or nozzles .to the ,point at ments .in .spinning .cells as heretofore construct- Whichtheyemerge fr omthe chamber is .only very ed, .but fis preferably .of Ithe same or of greater short, .so that the laments Vneed .only `travel a length. lI ihe .total distance from the jets or .relatively short `distance in the chamber. v nozzles to the guide, roller V-or like device, and

The present invention is based on the 4f-act that, from the guide, roller .or like device to the point 45 .for.certainpurposeaadvantageis presented when of .exit for the filaments must not vbe less than 3 the path traversed by the lamentslduring their yards, .and is preerably 4 or 5 or even 6 yards passage from the `jets or nozzles to the .point .at or more.

which they leave the chamber is from 3 to 6 yards Other methods of .carrying .out the invention o0 or moreinilength. will readily suggest themselves. For instance, 50

According to the invention, a process for the it is possible to extend the foot of the spinning production of 'laments or `threads from solutions cell or chamber in a ,lateral -or a horizontal dio cellulose acetate or other cellulose derivative rection, while keeping its height the same as that comprises extruding lthe solutions downwards at present employed, the filaments being .caused into a spinning chamber, .causing the laments vto pass around .a guide, roller vor like device in the lower part of the spinning cell and thence in a lateral direction through the lateral extension thereof.

Instead of or in addition to employing a guide, roller, or other device to divert the iilaments in the spinning cells or chambers so as to cause them to follow paths of 3 to 6 yards or more from the jets or nozzles to the points at which they leave the cells or chambers, the height of the cells or chambers may be increased to such an extent that the faces of the jets or nozzles are from 3 to 6 yards or more or much more above the point at which the filaments issue from the chamber.

In apparatus in which the filaments are caused to pass around a guide, roller or like device within the spinning cell, the arrangement may be such as to provide for a separate control of the extent to which the filaments are drawn out or stretched before they reach the guide, roller or like device and the extent to which they are drawn out after they have passed said device. For example, the roller may be driven at an appropriate speed, the filaments being if necessary lapped around the roller, so that the superficial speed of the roller is imparted to the filaments.

The invention is applicable to the production of filaments of any desired characteristics, whether round, or roundish, ribbon-like, voluminous, or cellular or tubular in structure. While the invention is particularly applicable to the production of filaments or threads having a basis of cellulose acetate, it may also be used for the manufacture of filaments or threads from solutions containing cellulose formate, propionate or butyrate, or thiocarbamic or alkoxy-alkacyl esters of cellulose, or methyl, ethyl or benzyl cellulose, or the corresponding condensation products of cellulose and glycols or other polyhydric alcohols, or other substitution derivatives of cellulose that are capable of being formed into artificial filaments or threads by evaporative or dry-spinning methods.

Referring to the accompanying drawing Figs. 1 and 2 illustrate apparatus for carrying out the process according to the invention, alternative methods for causing the filaments or threads to follow paths of 3 or more yards in length being indicated.

In Fig. 1, I is a spinning nozzle arranged at the upper end of a cell or chamber 2. Evaporative medium, such as air, enters the cell 2 by the inlet 3, the medium being heated on entering the cell, or heated inside the cell by means such as the heating pipes 4. The filaments 5 extruded from the nozzle I are solidified in their passage through the evaporative medium and leave the cell in the form of a thread 8 through an opening 1.

The filaments 4 in their passage through the cell travel to a point below the level of the opening 1, and a guide roller 8 is arranged near the bottom 9 of the cell to receive the threads and enable them to return in an upward direction to the opening 1. The length of the cell and the position of the roller 8 are such that the more or less tortuous path traversed by the filaments from the nozzle I to the roller 8 and from ,the roller to the opening 1 is at least 3 yards, and preferably 4 yards or more in length.

In addition to the advantage of high solvent recovery offered by the path of 3 yards or more during which the filaments are exposed to the evaporative medium, the evaporative power 0f the medium may be enhanced by the employment of the collector devices described in U. S. patent application Serial No. 236,448 filed 29th November, 1927. One such device is shown in the gure and consists of a cylindrical tube I0 through which the evaporative medium has to pass on its Way to a suction draw-off II, the medium being thereby constrained to pass through the immediate vicinity of the nozzle I. The draw-off II comprises an annular pipe perforated on its underside with a series of holes I2 and disposed coaxially with the pipe I3 that supplies the spinning solution to the nozzle I. The draw-off II is arranged somewhat above the level of the nozzle and assists the collector device I0 in bringing the evaporative medium through the neighbourhood of the nozzle. A tube I4 connects the draw-off II to a pipe I5 that communicates through a valve I6 with a header I1, the valve I6 being controlled by a handle I8 to regulate the iiow of the evaporative medium in conjunction with a flow-meter I9 connected to the pipe I5, as is described in U. S. patent specification No. 1,541,104.

Instead of employing the guide roller 8 as is shown in Fig. 1 to ensure that the filaments follow a path of at least 3 yards in length, the height of the nozzle I above the opening 1 may be increased as is shown in Fig. 2 to at least 3 yards, and preferably 4 yards or more, and the filaments may then be led directly from the nozzle I to the opening 1, the requisite length of path according to the invention being furnished by this disposition of the nozzle I and the opening 1. The last-mentioned arrangement does not require the bottom of the cell 2 to be much below the level of the opening 1, suitable relative positions of the bottom 9 and the inlet 3 for the evaporative medium being shown in Fig. 2.

In both figures, the thread 6 after leaving the cell 2 by the opening 1 passes over or round a feed roller 20 and proceeds to any suitable winding or a twisting and winding device, such as the cap-spinning device 2|.

An inspection opening 22 is provided in the cell at about the level of the nozzle I to provide access to the nozzle. The tube I0 is preferably slidably mounted in a funnel 23 so as to be readily adjustable, and also movable away from the nozzle. Heating means 24 may be provided immediately below the collector device I0.

The roller 8 may be positively driven in any convenient manner and may rotate at a speed higher than the speed of extrusion of the i'llaments, thereby stretching the filaments in their passage from the nozzle I to the roller 8. The roller 20 is preferably positively driven and may still further stretch the filaments after they have left the roller 8.

It is to be understood that the foregoing details are merely given by way of illustration and that many variations may be made therein without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is:-

1. A process for spinning artificial iilaments or threads from solutions of cellulose acetate or other cellulose derivatives, said process comprising spinning the solutions into a current of evaporative medium secluded from the atmosphere, causing the laments or threads to follow a path of at least 3 yards in length through said evaporative medium, withdrawing said iilaments or threads from said evaporative medium, and finally winding the filaments or threads.

2. Apparatus for the spinning of artificial filaments or threads by the evaporative method, comprising a spinning chamber, at least one spinning nozzle in said chamber, winding apparatus located outside the chamber, an outlet from the chamber, and guide means for the filaments or threads in the chamber below the level of said outlet, the apparatus presenting a path from the spinning nozzle round the guide means to the said outlet at feast 3 yards in length,

3. In the spinning of articial laments from solutions of derivatives of cellulose by extruding the laments into a current of heated gaseous medium secluded from the atmosphere, the step of causing the filaments to pursue a. tortuous extended path of at least three yards in length through said heated medium, withdrawing said filaments or threads from said evaporative medium, and finally Winding vthe laments or threads.

4. Apparatus for the spinning of artificial filaments by the evaporative method, said apparatus comprising at least one spinning nozzle and a. spinning chamber adapted to contain said nozzle and provided with an outlet for the iilaments extruded into the chamber, said chamber being further adapted to afford to the filaments between said nozzle and said outlet an extended path of at least three yards in length.

5. Apparatus for the spinning of articial lilaments by the evaporative method, said apparatus comprising at least one spinning nozzle and a spinning chamber adapted to contain said nozzle provided with an outlet for the filaments extruded into the chamber, and guide means Within said chamber adapted to conduct the laments between said nozzle and said outlet along an extended path of at least three yards in length.

HENRY DREYFUS. 

